Method and apparatus for opening and closing hatch covers

ABSTRACT

A hatch cover including a plurality of cover panels each of which is aligned with the next panel in closed position by means of male and female members respectively provided on one panel and the other so as to seal accurately a gasket between a pair of adjacent panels. Means are provided for bringing each panel into tilted position when it is separated from the adjacent panel after all the panels are lifted up in one block from the hatch coaming so as to permit each panel to be moved between the position above a hatch coaming and the storing position with its gasket maintained at a level lower than that of a disengaged gasket engaging bar mounted on the adjacent panel.

United States Patent 1 lto [ Aug. 14, 1973 METHOD AND APPARATUS FOR OPENING AND CLOSING HATCH COVERS [21] Appl. No.: 202,880

[30] Foreign Application Priority Data Nov. 30, 1970 Japan 45/105055 [52] US. Cl. 49/127, 114/202 [51] Int. Cl. E05d 15/26 [58] Field of Search 49/371, 125, 127;

[56] References Cited UNITED STATES PATENTS 2,891,500 6/1959 Appleton et a1. 114/202 F ORElGN PATENTS OR APPLICATIONS 1,063,415 3/1967 Great Britain 160/188 1,132,359 10/1968 Great Britain 114/202 Primary Examiner-Kenneth Downey Attomey-Anthony A. OBrien [5 7] ABSTRACT A hatch cover including a plurality of cover panels each of which is aligned with the next panel in closed position by means of male and female members respectively provided on one panel and the other so as to seal accurately a gasket between a pair of adjacent panels. Means are provided for bringing each panel into tilted position when it is separated from the adjacent panel after all the panels are lifted up in one block from the hatch coaming so as to perrnit each panel to'be moved between the position above a hatch coaming and the storing position with its gasket maintained at a level lower than that of a disengaged gasket engaging bar mounted on the adjacent panel.

6 Claims, 15 Drawing Figures 9 filer- Ash-=2;

PAIENIEU Am: I 4m:

SHEET 3 BF 9 PAIENIEDAUB 1 ms SHEEI '4 OF 9 w m nw METHOD AND APPARATUS FOR OPENING AND CLOSING HATCH COVERS The present invention relates to a hatch cover, more particularly a hatch cover including a plurality of cover panels constructed to be lifted up from a hatch coaming in one block with each panel engaged with an adjacent one, thereafter separated one from each other, and then moved along rail members on the hatch coaming with a gasket of each panel maintained at a level lower than that of an engaging bar mounted on the adjacent panel during an opening operation.

In the prior art hatch cover of the type including a plurality of cover panels, it is usual practice to drive wedges one by one into each of cleat members located on the cover panel at a predetermined spacing along mating edges between a pair of adjacent panels so as to cause the gasket on one panel to be accurately aligned with an engaging bar mounted on the adjacent panel. Those wedges are uneconomical since a great deal of time and labour will be required for opening and closing the hatch cover. Moreover, those wedges may hamper loading of deck cargo. Further, since each panel is handled with its gasket located oppositely to the engaging bar mountedon the adjacent panel for a short distance without being'engaged together during opening and closing operations in use of the prior art hatch clos ing devices of this kind, the engaging bar may unnecessarily come in contact with or rub the gasket and hence mar the latter during the movement, particularly during operation of each panel at the storing position. The present invention has been devised to overcome disadvantages of the conventional hatch covers mentioned above.

It is an object of the present invention to provide a hatch closing device including a plurality of cover panels constructed such that an engaging bar mounted on one panel will be engaged with a gasket provided on a adjacent panel along an engaging edge between a pair of adjacent panels during closing operation by aid of suitable aligning means and in addition the gasket will be held at a level different from that of the engaging bar when the former is separated from the latter so as to keep the former positively away from the latter except for the time during which both are engaged together.

According to the present invention, there is provided a method of opening and closing hatch covers rolling along rail members on a hatch coaming including the steps of lifting up a plurality of cover panels from the hatch coaming in one block with an engaging bar mounted on one panel engaged with a gasket provided on an opposite panel along engaging edges between a pair of adjacent panels, separating said engaging bar on each panel from said gasket on an adjacent panel, tilting each panel so as to maintain said engaging bar on one panel at a level different from that of said gasket on the adjacent panel, and then transferring each panel successively to storing position so as toopen the hatch cover.

Also, there is provided an apparatus for opening and closing a hatch cover rolling along rail members on a hatch coaming, including a plurality of cover panels placed horizontally side by side on a hatch coaming each having a gasket on one side and an engaging bar on the other side thereof, a pair of rolls mounted on each panel on each side adjacent to said gasket and said engaginging bar, a pair of lifting levers mounted on said hatch coaming adjacent to a pair of openings provided on the same receiving said pair of said rolls on each panel in closed position, one of said lifting levers intended for the roll adjacent to said gasket being provided with a two position cam surface corresponding to lifted and lowered positions of said roll, the other of said lifting levers intended for the roll adjacent to said engaging bar being provided with a three position cam surface corresponding to lifted, intermediate and lowered positions, and an actuating rod provided with rotatable actuating rollers engageable with said cam surfaces on each lifting lever and reciprocating in a direction parallel to that of movement of said cover panels.

Now, one preferable embodiment according to the present invention will be described in detail by way of example hereinafter with reference to the accompanying drawings, in which FIGS. la and lb are side elevation views showing the hatch cover according to the present invention, respectively, in closed and lifted positions,

FIGS. 20 and 2b are cross-section views in enlarged scale showing watertight sealing means and aligning means according to the present invention, respectively, in engaged and disengaged positions,

FIGS. 3a and 3b are side elevation views in enlarged scale showing a roll adjacent to a gasket and a lifting lever engageable therewith respectively in lowered and lifted positions, 7

FIGS. 4a, 4b and 4c are views similar to FIGS. 34 and 3b showing particularly rolls and lifting levers adjacent to an engaging bar, respectively, in lowered, lifted and intermediate positions,

FIG. 5 is a side elevation view showing an actuating rod and a hydraulic jack for actuating the same,

FIG. 6a is a vertical section view showing the roll, a rail member, an opening provided in the rail member and the lifting lever,

FIG. 6b is a plan view showing the rail member provided with openings for receiving the roll,

FIG. 7 is a schematic view showing a pair of hydraulic jacks for driving hatch cover panels in opening and closing directions,

FIG. 8 is a side elevation view showing-connections of hatch cover handling wire to an actuating lever, and

FIG. 9 is a side elevation view showing the hydraulic jack in FIG. 7 in hatch closing position.

Referring to drawings, particularly FIG. la, there are shown a plurality of hatch cover panels la, lb, 10, 1d placed side by side horizontally in closed position on the hatch coaming.

Each cover panel la, lb, 10 are provided respectively with rolls (3a, 3a), (3b, 3b), (3c, 3c'.), rolling along rail members 2 mounted on the coaming. Rolls 3a, 3b, 3c are mounted respectively on each panel la, 1b, 1c, at the left end thereof or on the side having an engaging bar mounted thereon. Rolls 3a, 3b, 3c, are mounted respectively on each panel at the right end thereof or on the side having a gasket mounted thereon. The rail member 2 is provided with openings 4a, 4a, 4b, 4b, 4c, 40' for receiving rolls 3a, 3a, 3b, 3b, 30, 3c on the panel la, lb, 1c in closed position thereof. When those rolls 3a, 3a, 3b, 3b, 3c, 3c fall down into corresponding openings 40, 4a, 4b, 4b, 4c, 40' on the rail member 2, the whole panels Ia, ab, ac will be lowered until a gasket 60 mounted on an aggregate panel in the periphery thereof is engaged with an engaging bar (or compression bar) 61 mounted on the rail member 2 to seal the hatch opening (SEE FIG. 6a). Hook means 5a, 5b, 5c, are rotatably mounted on the hatch coaming so as to be engaged with socket members 60, 6b, 6c on cover panels thereby locking those panels in sealed position.

According to the present invention, sealing means between a pair of adjacent panels are located in position A, A as shown in FIG. 1a so as to seal a connected portion of both panels, for instance, panels la and 0b in watertight manner. As shown in FIG. 2a, the sealing means includes a gasket 7a is mounted on the panel la along one edge lla thereof, and a compression bar 8b mounted on the adjacent panel lb along one edge 12b opposed to said edge lla of the panel la. The compression bar 8b is brought into engagement with the gasket 7a to seal the connected portion of both panels. Both the gasket 7a and the compression bar 8b are extending transversely of the hatch opening. A plurality of female aligning block or socket members 90 are provided at a predetermined spacing on the panel In along one edge lla thereof adjacent to the gasket 7a. The same number of male or pin members are mounted on the adjacent panel lb along one edge 12b thereof in position opposite to the female blocks 9a, so as to be fitted into the latter. The female blocks 9a and the male members 10 are mounted respectively on both panels la and lb at the same spacing as that of wedges conventionally used in way of connecting portion of both panels. In other word, conventional wedges are replaced by the pin member and socket means of the present invention so as to connect both panels in accurately aligned condition. Hence, when all the male members 10 on the panel lb are fitted into corresponding female socket members 9a on the opposite panel la, both panels la, lb and hence the gasket 70 and the compression bar 8b will be automatically and accurately engaged with each other to seal the connected portion of both panels. As shown in FIGS. and 2b, the inner surface of the female socket members 90 has a slight taper so as to diverge toward the entrance of the cavity, and tip end 106 of the male member 10 is also tapered in order to facilitate the engaging of both members.

As shown in FIG. 2a, one edge 12b of the panel lb will be elevated at a level higher than that of the edge lla of the panel 10 by means of a mechanism to be described hereinafter in a condition in which both panels la and lb are separated from each other. The relative position of one panel with reference to the adjacent panel as shown in FIGS. lb and 2b is unique to the present invention. The reason for maintaining the edge 12b of one panel lb having the compression bar 8b mounted thereon at a level higher than that of the edge lla of the opposite panel la having the gasket 7a mounted thereon is for preventing said male members 10 and female members 9c from being fitted together again thereby hampering a pivotting motion of each panel at the storing station ST when those panels are transferred thereto (SEE FIG. 8 and 9). Another reason is for preventing the compression bar 8b from coming into contact with the gasket 70 during the movement, particularly during pivoting motion of the panels at the storing station ST.

As shown in FIG. lb, left hand rolls 3a, 3b, 3c, are mounted respectively on the panels la, lb, 10, at a level lower than that of right hand rolls 3a, ab, 3c, Therefore, when all of the rolls are lifted up on a level flush with upper surface of the rail member 2 (position in FIG. lb), the left end of the panel lb will be held in a position higher than the right end of the adjacent panel la. That is, there will be produced a step between a pair of adjacent cover panels. The situation is the same with any other pair of adjacent panels.

As shown in FIGS. la and lb, pivotal levers 50a, 51a, 50b, 51b, 50c, 51c, are pivotably mounted on the rail member 2 in the lower side thereof respectively adjacent to said openings 4a, 4a, 4b, 4b, 4c, 40', by means of pins 53 and lug means 52 on the rail member 2. When each pivotable lever 50a, 51a, 50b, 51b, 50c, 51c, is pivotted clockwise about the pin 53 viewed in FIG. 4b, it will have its upper surface fitted into corresponding opening 4a, 4a, 4b, 4b, until its upper surface becomes flush with the upper surface of the rail member 2. Therefore, each of the pivotal levers will lift up each roll dropped down into the opening of the rail member up to the level of the upper surface of the same.

As shown in FIGS. 40, 4b, and 4c, pivotal levers 50a, 50b, 50c, are mounted on the rail member 2 respectively adjacent to the left end, that is, adjacent to compression bar 8b of each panel. Each of pivotal levers will be turned to three positions, i.e., lowered, intermediate, and lifted positions by action of actuating rollers 56 which will be described in detail hereinafter. For this purpose, each of pivotal levers 50a, 50b, 50c, is provided with a cam surface 54a including three different levels X, Y, Z as shown in FIG. 4b.

As shown in FIGS. 3a and 3b, each of the pivotal levers 51a, 51b, 51c, is mounted on the rail member 2 respectively adjacent to the right end, that is, adjacent to the gasket 7a, 7b, 7c, of each panel. Each of pivotal levers 51a, 5 lb, 51:: will be moved between lowered and lifted positions by action of actuating rollers 56 to be described hereinbelow. For this purpose, each of pivotal levers 51a, 51b, 51c, is provided with a cam surface 55a having two different levels X, Z as shown in FIG. 3b.

As shown in FIGS. la and lb, an actuating rod 13 is slidably mounted on the rail member 2 in the lower side thereof by means of a number of guide supports l4, l4 fixedly mounted on the rail member at a suitable spacing so as to be rcciprocated horizontally. The actuating rod 13 is connected to a hydraulic jack 15 at one end thereof by means of a pin 16. The hydraulic jack 15 is connected to a bracket 25 on the deck at one end opposite to that connected to the actuating rod [3 by means of a pin 26 (FIG. 5).

The actuating rod 13 is provided in a position adjacent to each of pivotal levers 50a, 50b, 51a, 51b, with rotatable rollers 56. Each of rotatable rollers 56 is engageable with the cam surface 54a or 55a on respective corresponding pivotal levers. Accordingly, when the actuating rod 13 is moved horizontally by action of the hydraulic jack 15, each actuating roller 56 will actuate its corresponding pivotal lever, engage the latter in either one of two different levels X, Z of the cam surface surface 55a, and in either one of three different levels X, Y, Z of the cam surface 54a dependent upon the position of the rollers 56.

FIGS. 6a and 6b show the openings 4a provided on the rail member 2 and the manner in which the roll 3a is lifted up by the pivotal lever 50a which is actuated upwardly through the opening 4a by action of the actuating roller 56 mounted on the actuating rod 13.

FIG. 8 shows a connection of handling wires for the panels, including a closing wire 29 for moving the rightmost panel In to the left by utilizing the horizontal motion of the actuating rod 13 so as to bring all the panels into closely fitted condition, and an opening wire 25 for moving the panel In to the right. The opening wire 25 is connected at one end to the right end 23 of the panel In by means of a shackle 24, and connected at the other end to a free end 13E of the actuating rod 13 after passing about a sheave 22 mounted on the storing station ST. Each panel is connected to adjacent panels by means of suitable chains or links (represented by a dashed line in FIGS. 1a and 1b). Therefore, when the actuating rod 13 is moved to the left, the panel In willbe moved toward the storing station, thus commencing a hatch opening operation. The closing wire 29 is connected at one end to a lug means 26 on the panel 1n, led to the left, passed about a sheave 27 mounted on the deck and then connected at the other end to the actuating rod 13 at one point 28 thereof. Accordingly, when the actuating rod 13 is moved to the right, the panel In will be driven to the left thereby bringing all the panels into closely fitted condition.

FIGS. 7 and 9 show a device for causing each panel to be closely fitted to and/or separated from the adja cent one, which is used for the same purpose as the panel handling wires 25, 29, and will drive the cover panel along the rail member, and bring the compression bar 86 into contact with the gasket 7a and fit the pin members into the socket members 9a (FIG. 2a). A pair of lug means and 208 are mounted on the panel In which is located adjacent to the storing station ST. A pivotal arm 18 is rotatably mounted on a suitable support (not shown) on the deck by means of a pin 21. When the pivotal arm 18 is rotated counterclockwise as viewed in FIG. 7 with its tip end engaged with lug means 208 in the rightside of the latter, the panel In will be moved to the left. When the pivotal arm 18 is rotated clockwise with its tip end engaged with lug means 20P in the left side thereof, the panel 1n will be moved to the right. The pivotal arm 18 is actuated by a pair of hydraulic cylinders 19, l9. A suitable amount of clearance is provided between the pivotal arm 18 and each of lug means 20F and 205, so as to cause the panel'ln to be actuated smoothly.

In describing the operation of the apparatus according to the present invention, it is assumed first that all of the cover panels 1a, 1b, 1c, are held in watertight closed position with the compression bar 8b engaged with the gasket 7a and with the pin members 10 fitted into the socket members 9a as shown in FIG. 2a. A set of the pin members 10 and the socket members 9a will act similarly to conventional wedges providedalong a connecting edge between a pair of adjacent panels, as described hereinabove. In the closed position, all the rolls 3a, 3a, 3b, 3b, 3c, 30', are dropped down through the openings 40, 4a, 4b, 4b, 4c, 4c, on the rail and are in their lowest position. All of the actuating rollers 56 mounted on the actuating rod 13 are not raising the pivotal lever 50a and 51 a (SEE FIG. 3a, 4a). Now, when the actuating rod 13 is moved to the left by means of the hydraulic jack 15, the actuating roller 56 on the rod 13 will come into contact with the cam surface X of the pivotal lever 51a and pivot the pivotal lever 51a clockwise about the pin 53 as viewed in FIG. 3b thereby lifting up the roll 3a of the panel to the level flush with the upper surface of the rail member (FIG.-

3b). The operation is the same with the other rolls 3b, 3c, On the other hand, the pivotal lever 50b will be actuated by the actuating roller 56, which is in contact with the former in the intermediate cam surface Y, and hence lift up the roll 3b mounted on the panel up to the intermediate position as shown in FIG. 4c. Thereafter, the pivotal lever 50b will be pivoted further about the pin 53 up to the elevated position as shown in FIG. 4b. In the position as shown in FIG. 4b, all the panels are lifted up as one block connected together, and then separated apart with the compression bar 8b of one panel disengaged from the gasket 7a of the adjoining panel. In the position as shown in FIG. 4b, the roll 3b is placed on the upper surface of the rail but is mounted on the panel at a level lower than that of the roll 3a as described hereinabove. Therefore, when both rolls 3!; and 3a are placed on the upper surface of the rail 2, the left end of the panel 1b is maintained at a level higher than that of the right end of the adjoining panel 1a with the panel lb in tilted position. Hence, the compression bar 8b is located higher than the gasket 7a as shown in FIG. 2b; At this point, it is noted that when the actuating rod 13 is moved a predetermined distance, the point of contact between the actuating roller 56 and the pivotal lever 50b will be shifted from the surface Z to the surface X through the surface Y (FIG. 4b), while the point of contact between the actuating roller 56 and the pivotal lever 510 will be shifted merely from the surface Z to the surface X (FIG. 3b). Each panel is transferred to the storing station ST in a tilted position.

The operation of the apparatus according to the present invention will be summarized as follows;

Contact Between (In position III, the eompresser bar is mparated from the gasket and the pin member is disengaged from the socket means) In closing the cover panels, operation will be carried out in reverse direction. Each panel is brought back to the coaming, until rolls of each panel are placed on top of the corresponding pivotal levers. Each panel is in tilted position during transferring. Then, when the actuating rod 13 is moved to the right, the rolls 3a, 3b, 3c, will be dropped down to the intermediate level as shown in FIG. 10 while the rolls 3a, 3b, 3c, remain on the level of the rail member 2, thus bringing each tilted panel into horizontal position. Thereafter, when the lever 18 is swung counterclockwise as viewed in FIG. 7 by means of the hydraulic jack 19, each panel is pushed successively to the left with the compression bar brought into engagement with the gasket, and then all the panels are lowered down to the top of the hatch coaming simultaneously in one block.

What is claimed is:

1. A method of opening hatch covers which include a plurality of cover panels movable along rail members on a hatch coaming, with adjacent panels having an engaging bar mounted on one panel engaged with a gasket provided on the opposite panel along engaging sides thereof, comprising the steps of lifting up the plurality of cover panels from the hatch coaming in one block, separating said engaging bar on each panel from said gasket on the adjacent panel, tilting each panel so as to maintain said engaging bar on one panel at a level different from that of said gasket on the adjacent panel, and then transferring each panel successively to storing position so as to open the hatch cover.

2. An apparatus for opening and closing a hatch cover movable along rail members on a hatch coaming, comprising a plurality of cover panels placed horizontal side by side on a hatch coaming each having a gasket on one side and an engaging bar on the other side thereof, a pair of rolls mounted on each panel on each side adjacent to said gasket and said engaging bar, a pair of lifting levers mounted on said hatch coaming adjacent to a pair of openings provided on the same receiving said pair of said rolls on each panel in closed position, one of said lifting levers intended for the roll adjacent to said gasket being provided with a two position cam surface corresponding to lifted and lowered positions of said roll, the other of said lifting levers intended for the roll adjacent to said engaging bar being provided with a three position cam surface corresponding to lifted, intermediate and lowered positions, and an actuating rod provided with rotatable actuating rollers engageable with said cam surfaces on each lifting lever and reciprocable in a direction parallel to that of movement of said cover panels, wherein said roll located on each panel adjacent to said engaging bar is mounted at a level lower than that of the roll located on said panel adjacent to said gasket causing said engaging bar to be maintained at a level higher than that of the gasket on the opposite panel when all of the rolls are lifted up to the level of the upper surface of said rail members.

3. An apparatus for opening and closing a hatch cover as described in claim 2, wherein each panel is provided adjacent to said engaging bar with a number of pin members projecting outwardly from end edge of said panel, the other panel adjacent to said panel is provided oppositely to said end edge with same number of female members, thereby causing both panels to be fitted together in accurately aligned condition due to engagement of said pin member with said female member so as to bring said engaging bar into a position accurately aligned with said gasket.

4. An apparatus for opening and closing a hatch cover movable along rail members at a hatch coaming, comprising a plurality of cover panels placed side by side on a hatch coaming with adjacent panels having an engaging bar mounted on a side of one panel for engagement with a gasket provided on an opposed side of the opposite panel, a pair of rolls mounted on each panel adjacent each side thereof, with the rolls adjacent one side of each panel mounted at a higher level than that of the rolls adjacent the other side of each panel, lifting means mounted adjacent to openings provided in said rail members for receiving said pairs of rolls on each panel and selectively positioning same between lowered and lifted positions, with said rolls disposed in said rail openings when at said lowered position such that the cover panels associated therewith are in closed position relative to said hatch coaming, and said rolls disposed on the level of the surface of said rail members when at said lifted position such that each of the cover panels associated therewith are in opening position'for movement along said rail members in a tilted position to thereby maintain the separated gasket and engaging bar of adjacent panels at different levels during such opening movement.

5. An apparatus for opening and closing a hatch cover as described in claim 4 wherein said lifting means includes a pivotable lifting lever for receiving each of said rolls having a two position cam surface, and actuating means including an actuating roller engaging each cam surface for selectively positioning said lifting levers at said lowered and lifted positions.

6. An apparatus for opening and closing a hatch cover as described in claim 5 wherein the lifting levers receiving the rolls adjacent said other sides of each panel have an intermediate cam surface engageable by said actuating rollers for leveling said cover panels at an intermediate lifted position to enable uncoupling of the gaskets and engaging bars therebetween.

, t i fi 

1. A method of opening hatch covers which include a plurality of cover panels movable along rail members on a hatch coaming, with adjacent panels having an engaging bar mounted on one panel engaged with a gasket provided on the opposite panel along engaging sides thereof, comprising thE steps of lifting up the plurality of cover panels from the hatch coaming in one block, separating said engaging bar on each panel from said gasket on the adjacent panel, tilting each panel so as to maintain said engaging bar on one panel at a level different from that of said gasket on the adjacent panel, and then transferring each panel successively to storing position so as to open the hatch cover.
 2. An apparatus for opening and closing a hatch cover movable along rail members on a hatch coaming, comprising a plurality of cover panels placed horizontal side by side on a hatch coaming each having a gasket on one side and an engaging bar on the other side thereof, a pair of rolls mounted on each panel on each side adjacent to said gasket and said engaging bar, a pair of lifting levers mounted on said hatch coaming adjacent to a pair of openings provided on the same receiving said pair of said rolls on each panel in closed position, one of said lifting levers intended for the roll adjacent to said gasket being provided with a two position cam surface corresponding to lifted and lowered positions of said roll, the other of said lifting levers intended for the roll adjacent to said engaging bar being provided with a three position cam surface corresponding to lifted, intermediate and lowered positions, and an actuating rod provided with rotatable actuating rollers engageable with said cam surfaces on each lifting lever and reciprocable in a direction parallel to that of movement of said cover panels, wherein said roll located on each panel adjacent to said engaging bar is mounted at a level lower than that of the roll located on said panel adjacent to said gasket causing said engaging bar to be maintained at a level higher than that of the gasket on the opposite panel when all of the rolls are lifted up to the level of the upper surface of said rail members.
 3. An apparatus for opening and closing a hatch cover as described in claim 2, wherein each panel is provided adjacent to said engaging bar with a number of pin members projecting outwardly from end edge of said panel, the other panel adjacent to said panel is provided oppositely to said end edge with same number of female members, thereby causing both panels to be fitted together in accurately aligned condition due to engagement of said pin member with said female member so as to bring said engaging bar into a position accurately aligned with said gasket.
 4. An apparatus for opening and closing a hatch cover movable along rail members at a hatch coaming, comprising a plurality of cover panels placed side by side on a hatch coaming with adjacent panels having an engaging bar mounted on a side of one panel for engagement with a gasket provided on an opposed side of the opposite panel, a pair of rolls mounted on each panel adjacent each side thereof, with the rolls adjacent one side of each panel mounted at a higher level than that of the rolls adjacent the other side of each panel, lifting means mounted adjacent to openings provided in said rail members for receiving said pairs of rolls on each panel and selectively positioning same between lowered and lifted positions, with said rolls disposed in said rail openings when at said lowered position such that the cover panels associated therewith are in closed position relative to said hatch coaming, and said rolls disposed on the level of the surface of said rail members when at said lifted position such that each of the cover panels associated therewith are in opening position for movement along said rail members in a tilted position to thereby maintain the separated gasket and engaging bar of adjacent panels at different levels during such opening movement.
 5. An apparatus for opening and closing a hatch cover as described in claim 4 wherein said lifting means includes a pivotable lifting lever for receiving each of said rolls having a two position cam surface, and actuating means including an actuating roller engaging each cam surface for selectively positioning said lifting levers at said lowered and lifted positions.
 6. An apparatus for opening and closing a hatch cover as described in claim 5 wherein the lifting levers receiving the rolls adjacent said other sides of each panel have an intermediate cam surface engageable by said actuating rollers for leveling said cover panels at an intermediate lifted position to enable uncoupling of the gaskets and engaging bars therebetween. 